I feel this is pretty low on the list of things I want from a test. Regressions should be rare; if you get a test failure when you break something's public API

I feel this is pretty low on the list of things I want from a test. Regressions should be rare; if you get a test failure when you break something's public API then that is already a success - we had the right test case! That you then maybe need to spend a few minutes finding out exactly what is failing, I can live with that.